CN1185581C - Evolution storage system and its evolution method - Google Patents

Abstract

The invention discloses an evolution storage system and an evolution method thereof. The system includes a storage library and a processor, and the storage library is divided into running, standby and disabled storage pools; the processor is provided with: a storage service device, a data I/O and distribution characteristic analysis device, a decision analysis device, a storage device management device and a user management device. The invention can automatically select the most suitable system organization scheme for the current environment according to the change of the storage system environment and its own state during the evolution process, and maintain the dynamic balance of the system. The system will not be unable to adapt to the needs of current applications due to outdated storage devices, and the installation, configuration, and expansion of the entire system are also very simple and easy, so the external characteristics presented to users are that the system gets better as it is used, and its performance will not Instead of declining over time, it is constantly improving, and has extremely high availability and good maintainability. It is a very good storage management solution in the field of mass storage.

Description

An evolution storage system and evolution method thereof

technical field

The invention belongs to the technical field of data storage, and in particular relates to an evolutionary storage system and an evolutionary method thereof, that is, a technique for managing storage resources in a mass storage environment.

Background technique

The enterprise-level mass storage system used in the network environment faces the following challenges: the explosive growth of digital information, the increasing importance and security of data, a large number of user groups and multimedia applications have huge pressure on access performance, 24×7 The service requirements of the company require extremely high availability and maintainability. The main technologies to meet this challenge are high-performance disk arrays, network attached storage (NAS, NetworkAttached Storage), storage area network (SAN, Storage Area Network), iSCSI (internet SCSI) and storage management software.

Although the above-mentioned technology is developing rapidly, it still has the following problems:

First, there is a common contradiction in the existing system, that is, the contradiction between the rapid development of components and the relatively fixed overall structure. Take the latest disk array technology as an example. Its components are disks. Once a disk fails, it will reconstruct the lost data on a new backup disk. However, no matter how many times the speed and capacity of the new disk are higher than other old disks, the overall performance of the reconfigured disk array will not be improved at all. The storage system with the current structure will not improve the overall performance due to the updated components. Therefore, with the advancement of technology, this system with stagnant performance will soon become obsolete, and users have to purchase new systems to meet the new requirements of applications;

Second, the current fixed data organization method makes the data distribution unadaptable to changes, and the overall performance of the system presents a tendency to degrade with use. For example, the performance of a disk gradually degrades as the number of repeated rewrites increases, which is a well-known fragmentation problem. Disk defragmentation on a single machine is very time-consuming, and the disk will not continue to be used during defragmentation, and it is more difficult to use the defragmentation program on the disk array;

Third, the organization mode of the system structure is relatively fixed, which cannot adapt to the diversity and dynamics of applications. For example, the level of the disk array (RAID level) is generally fixed after being set, and it is difficult to adapt to various applications of different natures. For example, RAID5 is set for transaction processing and has high performance, but it is not suitable for streaming media applications. Great fit.

The reason for the above problems is that the physical and logical organization of the existing storage system is a static structure, and the static organizational structure model cannot well describe the constantly changing system. This structure is often suitable for specific application needs, and lacks a mechanism to adapt to changing storage requirements.

Prior to this, some related technologies have been proposed to solve the optimization and management of storage resources.

For example, for the AutoRAID technology developed by Hewlett-Packard, see HP whitepaper, "HP AutoRAID: High-Performance Storage for the High-Availability NT Environment", http://www.hp.com.cn/prodserv/server/pcserver/whitepaper/ DOCS/au toraid.pdf , this technology is a multi-level RAID array technology that combines the advantages of different RAIDs. It puts the recently used data in the fast and high-performance disks stored in RAID 0/1, and saves less commonly used data. Data is placed on cost-effective disks stored in RAID5. AutoRAID technology can make the installation, configuration and expansion of the system easy. This technology no longer needs to transfer data to other disks in the array. Just install the new disk, and AutoRAID can automatically determine the size of the disk, and It is added to the disk array; the system can immediately use the space of the new disk and store more data in RAID 0/1 mode to improve system performance and access speed. In addition, AutoRAID can manage disk arrays composed of disks of different capacities. Dynamic data transfer is a major feature of HPAutoRAID. It is a set of control mechanisms inside the system that can continuously monitor the performance of the disk array and decide whether to keep the data in the cache, whether to store the data as RAID1, and whether to write the data. RAID5 array. These control mechanisms are able to adapt to different data situations and maintain high performance of the system. This feature is extremely useful in situations where the work environment is constantly changing.

However, this technology only optimizes storage resources at the level of dynamic distribution of data according to the frequency of use of data by applications, so the effect is still very limited.

Contents of the invention

The purpose of the present invention is to provide an evolutionary storage system that can overcome the above-mentioned defects, the system can make the capacity and performance of the storage system evolve with time, and is easy to implement and manage; the present invention also provides an evolutionary storage system for the above-mentioned system method.

In order to achieve the purpose of the above invention, an evolutionary storage system includes a storage library and a processor that manages the storage library. The physical storage devices in the storage library are divided into three states: running, standby and disabled, and are divided into running storage pools, A standby storage pool and a disabled storage pool; the processor is provided with: a storage service device for responding to a data I/O request sent by a computer node, providing a data storage service, and sampling the I/O data, and sending it to the data I /O and distribution feature analysis device; the data I/O and distribution feature analysis device is used to perform statistical analysis on the frequency of use of I/O data and the distribution characteristics of the physical location of the data in the storage library, and transmit the analysis results to decision analysis device; the decision analysis device is used to synthesize the use frequency and distribution characteristic results of the I/O data transmitted from the data I/O and distribution characteristic analysis device, and the storage device work performance result transmitted from the device, in the evolutionary rule base Select the evolution rule, obtain the control information formulated in the rule, and send the control command to the storage device management device; the storage device management device redistributes the data in the storage library or redistributes the storage device according to the operation command sent by the decision analysis device Perform regeneration processing; manage the storage device, maintain the mapping relationship table between the logical device unit identifier and the location number of the storage device, perform real-time sampling and analysis of the operation status information of the storage device, and feed back the performance analysis result to the decision analysis device; The system also includes a user management device for receiving the system I/O and distribution characteristic analysis information output by the data I/O and distribution characteristic analysis device, as well as the operation status information of each storage device output by the storage device management device, and communicates with decision analysis The device and the evolution rule base are connected.

An evolutionary method for the above-mentioned evolutionary storage system, the steps of which are:

(1) The system monitors each storage device in real time;

(2) Determine the status of the storage device:

(2.1) When the storage device is in the running state, check its operating performance. If the performance does not meet the requirements, the system will alarm, and select the storage device with performance and space that meets the requirements from the standby storage pool to the running storage pool, and replace the original device. The data on the storage device is reconstructed on the storage device; otherwise, continue to run and use;

(2.2) When the storage device is in the standby state, detect its operating performance, if the performance is lower than the specified value, transfer to the disabled storage pool, otherwise, transfer to the operating storage pool or maintain the original state as required;

(2.3) When the storage device is in a disabled state, check its physical performance, if the performance does not meet the requirements, replace it with a new storage device, otherwise format the storage device; then transfer the new or formatted storage device into Standby storage pool.

Unlike several existing mainstream storage technologies, such as RAID, DAS, NAS, SAN, iSCSI, etc., which only statically improve storage performance from the physical connection mode and I/O protocol of storage devices, the present invention draws lessons from biological system evolution and Based on the principle of dissipative structure, the design idea of evolutionary storage system is proposed. This is a system that can automatically select the most suitable system organization scheme for the current environment according to changes in the storage system environment and its own state during the evolution process to maintain the dynamic balance of the system. It not only solves the above problems, because the system can automatically adjust the management and organization strategies of the system according to changes in the environment, and can dynamically add new storage devices continuously, so that the system will not be unable to adapt to the needs of current applications due to outdated storage devices , the installation, configuration, and expansion of the entire system are also very simple and easy, so the external characteristics presented to users are that the system gets better and better with the use of time, and the performance will not decline over time, but will continue to improve, and has extremely High availability and good maintainability. It is a very good storage management solution in the field of mass storage.

In a word, the evolutionary storage method and its control system proposed by the present invention have the characteristics of capacity and performance evolving with time, and have extremely high availability and easy management, and are a new storage system concept. It meets the performance, capacity, availability, maintainability and scalability requirements of modern enterprise-level storage systems, and has a very broad application prospect.

Description of drawings

Fig. 1 is the structural representation of a kind of evolution storage system adopting the method of the present invention;

2 is a schematic structural diagram of a control system of an evolutionary storage system;

FIG. 3 is a schematic structural diagram of a specific implementation of the storage device management device in FIG. 2;

4 is a schematic diagram for illustratively showing the logical organization structure of storage units of the evolutionary storage system;

Fig. 5 is a schematic diagram showing that when a certain storage device in the evolutionary storage system fails, the system automatically switches the LDU identifier corresponding to the storage device to a certain storage device in the standby storage pool;

Fig. 6 is a flowchart of an evolution method for evolving a storage system.

Detailed ways

As shown in FIG. 1 , an evolutionary storage system includes a storage library 2 , a processor 3 , a switch 5 and a bridge 6 . Processor 3 may be a single processor, SMP (Symmetric Multiple Processors, symmetric multiprocessor), MPP (Massively Parallel Processors, parallel processing system), cluster or other network computing devices. Processor 3 may be supported by multiple registered devices, such as computer node 1 registered in the evolutionary storage system, which may be a single processor, SMP, MPP, cluster or other network computing devices. The storage library 2 includes a plurality of physical storage devices 4, and if the storage devices support SCSI interfaces, each physical storage device 4 is connected to a bridge 6 from SCSI (Small Computer Systems Interface) to FC (Fibre Channel, Fiber Channel). Since the data transmission rate of the SCSI channel and the number of connected storage devices are limited, the storage devices can also use FC interfaces. If the physical storage devices use FC interfaces, the bridge 6 can be a fiber channel switch. If the number of physical storage devices in the storage library 2 exceeds the range supported by a single SCSI channel or fiber channel, the SCSI channel or fiber channel can be connected in a two-stage cascade as shown in Figure 1, and the fiber channel switch 5 , and multi-level connection can also be used to expand the storage library 2 as required. Designate the physical storage devices of repository 2 as Logical Device Units (LDUs). The LDU identification of each physical storage device 4 is jointly determined by the SCSI channel (or FC channel) identification where the physical storage device is located and the location number of the device on the SCSI channel (or FC channel), and is unique in the storage library 2, For example, the location number (1, 1) may identify the first physical storage device on the first channel, and the LDU identifier of the storage device may be LDU_20. The mapping relationship table between the LDU identifier and the location number of the storage device 4 is maintained by the system and can be updated dynamically. The LDU in Fig. 1 is controlled by the processor 3, and addresses it uniformly. The storage resources of the entire storage system are managed by the processor 3 .

In repository 2, all storage devices are in three states: running, standby and disabled.

In work, the processor 3 communicates with the storage bank 2 through the SCSI bus using the SCSI protocol, or through the optical fiber adopting the Fiber Channel protocol, and transmits the data received from the processor 3 to the storage bank 2, and then transmits the data received from the processor 3 to the storage bank 2 Data is transferred from the repository 2 to the processor 3 .

The processor 3 monitors the working performance of the physical storage device 4 in the storage library 2 in real time, and determines the operating status of the storage device in the storage library according to the result. At the same time, feature analysis is performed on the input and output data of the storage library 2 to determine the location distribution of the data on the physical storage device.

As shown in Figure 2, during work, the data imported by computer node 1 is transmitted to storage library 2 through storage service device 10, and the data returned from storage library 2 is received by the device and output to computer node 1. The outside world provides reliable storage services. At the same time, the storage service device 10 samples the I/O data, and transmits the sampled data to the data I/O and distribution characteristic analysis device 9, and the device uses the frequency of I/O data and the physical location of the data in the storage library. Statistical analysis is performed on the distribution characteristics, and the analysis results are sent to the decision analysis device 8 . The storage device management device 7 is responsible for managing the storage devices in the storage library 2 , maintaining the mapping relationship table between the LDU identifier and the location number of the storage device 4 , and completing the operation commands sent by the decision analysis device 8 . The storage device management device 7 also samples and analyzes the running state information of the physical storage device 4 in the storage library 2 in real time, and transmits the performance analysis result to the decision analysis device 8 .

The decision analysis device 8 synthesizes the use frequency and distribution characteristic results of the I/O data transmitted from the data I/O and distribution characteristic analysis device 9, and the storage device work performance result transmitted from the storage device management device 7, in the evolution rule Select an evolutionary rule suitable for the current operating situation in the library 11, obtain the control information formulated in the rule, and send the control command to the storage device management device 7, and the storage device management device 7 will redistribute the data in the storage library or store The equipment is regenerated. If there are multiple applicable evolution rules in the evolution rule base 11, let these rules compete, that is, send the test data of each rule to the repository, and select the best rule according to the returned performance test results to optimize the system . To automatically optimize the performance of the storage system and realize the evolution function of the system itself.

During the working process, the data I/O and distribution characteristic analysis device 9 transmits the system I/O and distribution characteristic analysis results to the user management device 12 in real time, so that the user can monitor the data I/O characteristics of the system. Similarly, the storage device management device 7 transmits the collected running status information of the physical storage devices 4 in the storage library 2 to the user management device 12 in real time. The user can analyze the system running status according to all the collected system information, and can directly send system control commands to the decision analysis device 8 as needed, so as to optimize the performance of the system. For example, you can manually migrate the data of an application with high usage to a physical storage device with high performance.

During the working process, because the system will dynamically adjust the data distribution strategy according to its own conditions and external data access characteristics, the decision analysis device 8 will transmit the data distribution information in the storage library 2 to the storage service device 10 in real time, so that the storage service The device can provide reliable storage services to the outside world.

The administrator can maintain the evolution rule base 11 through the user management device 12 during the operation of the evolution storage system. According to the running state of the storage system, if it is found that a new evolutionary rule needs to be added, the new evolutionary rule can be added to the evolutionary rule base 11 through the user management device 12 . Evolution rules that do not apply can also be modified or deleted as well.

Each device in FIG. 2 is set in the processor, but the user management device 12 can also be set on the computer node.

As shown in FIG. 3 , the storage device management unit 7 includes a storage device management control subunit 71 , a storage device performance monitoring subunit 72 , an LDU management subunit 73 , and a storage device maintenance subunit 74 .

The function of the storage device management and control sub-device 71 is to accept the command issued by the decision analysis device 8, send corresponding control information to the corresponding device, and complete the management function of the storage device. And the status information of the physical storage device 4 in the storage library 2 is fed back to the user management device 12 and the decision analysis device 8 respectively.

The storage device performance monitoring sub-means 72 monitors the performance of the storage devices in the storage library 2 (such as data throughput, average response time, read and write accuracy), and sends the results to the storage device management control sub-means 71, by The storage device management control sub-unit 71 transmits the results to the user management unit 12 and the decision analysis unit 8 respectively. The storage device management control sub-device 71 can decide whether to send alarm information to the user management device 12 according to the operation situation. During the working process, the storage device management control sub-device 71 can receive the commands sent by the decision analysis device, send control commands to the performance monitoring sub-device 72, and adjust the performance monitoring strategy.

The LDU management sub-device 73 receives the LDU dynamic configuration information transmitted from the storage device management control sub-device 71, maintains the mapping relationship table between the LDU identifier and the location number of the storage device 4, and transmits the corresponding information to the storage device 8 through the decision analysis device 8. Serving device 10 .

The storage device maintenance sub-unit 74 receives the storage device maintenance command issued by the storage device control sub-unit 71, and performs maintenance on the storage device in the storage library 2, such as formatting, file defragmentation and so on.

Fig. 4 shows a logical structure diagram of a repository in an evolutionary storage system. In repository 2, all storage devices are in three states: running, standby and disabled. The running storage pool 21 is a storage device 41 in a normal operating state, which is a storage space for providing data storage services in the system, and the standby storage pool 22 is a collection of storage devices that do not store data and are waiting to be used—that is, the standby storage device 42; Disabled storage pool 23 is a collection of retired storage devices—that is, disabled storage devices 43 .

In the embodiment shown in FIG. 4 , the system detects each storage device in the storage pool, determines the transition of different states of the storage device according to the state, and realizes the evolution of the physical structure of the system. For example, when the monitoring program finds that the physical performance parameter of the storage device 42 in the standby state is lower than the set value or when it cannot work, the storage device will be disabled, and the state of the storage device will be changed into disabled and turned into disabled. The storage pool 23 is waiting for manual or mechanical replacement; when the physical performance of the storage device 42 in the standby state in the standby storage pool 22 is greater than or equal to the set value, if the system requires the disk to provide storage services, the state of the storage device will be Running instead, go to running storage pools. Similarly, the monitoring program can monitor the storage device 41 in the running state. If the physical performance cannot meet the requirements, the useful data will also be transferred, and the storage device will be transferred to the disabled storage pool 23 . After the storage device 43 in the disabled storage pool is replaced or formatted, if the physical performance meets the requirements, it can migrate to the standby state or the running state. Through the state transition similar to metabolism of each storage device in the storage system, the physical storage devices that do not meet the requirements are continuously updated or replaced, and new physical devices that meet the requirements are added at the same time, which improves the operation performance and stability of the entire system, and enables The whole system has always been advanced, realizing the evolution of the physical structure of the system.

The storage devices in the running pool are stored in the form of storage device clusters. A storage device cluster is the basic logical storage unit in the system and provides a relatively stable and linear storage space. It is a collection of one or more homogeneous physical storage devices. Storage devices in the same storage device cluster have similar storage capacity and physical storage performance. Different storage device clusters can have different storage parameters, such as data block size. Storage devices in a storage device cluster are not necessarily physically adjacent. The number of storage devices in each storage device cluster can be changed dynamically, at least one. On the basis of ensuring a reliable storage space, a storage device in a storage device cluster can be replaced by another storage device with similar performance. When the number of storage devices in a storage device cluster changes or a storage device is replaced, the system automatically reconstructs data. A cluster of storage devices provides data access in the form of data blocks.

For example: in Figure 4, the logical device unit LDU_1 in the running state forms RAID5 together with LDU_2, LDU_3, LDU_4, and LDU_5, and the position number of LDU_1 is (2, 3). When the system finds that the working performance of LDU_1 does not meet the system requirements , it is not necessary to take out the storage device at the location and replace it with a new storage device as in the usual storage system. And only need to query the performance tables of all storage devices in the system in the storage device management device 7, such as finding that the storage device at position number (1, 5) meets the requirements of the system, then under the premise of ensuring data consistency, it will be located at ( 2, 3) The data on the storage device at the position is migrated or reconstructed to the storage device with the position number (1, 5), and the device is marked as LDU_1, the state is changed to the running state, and the LDU and the position number are updated at the same time. Mapping table. This ensures the reliability of the storage system. In addition, the state of the storage device at position (2, 3) is marked as disabled, and transferred to the disabled storage pool. As shown in Figure 5.

FIG. 6 depicts a flow chart of an evolutionary method that can be used in the above-mentioned storage system, that is, a set of evolutionary strategies for the evolutionary rule base. The method determines the transition of different states of the storage device according to the state, and realizes the evolution of the physical structure of the system. As shown in step 102, the evolutionary storage system monitors each storage device in the storage library in turn. In step 104, the system judges the running state of the storage device, if the state is running, go to step 106; if the state is standby, go to step 108; if the state is disabled, go to step 109.

In step 106, the system detects the operating performance (such as data throughput rate, average response time, and read and write correctness) of the storage device in the running state. , the I/O performance is lower than the threshold or the performance is lower than the running performance index due to too many file fragments in the device), then perform step 110; if it runs normally, that is, the working performance meets the system requirements, then go to step 102, and perform the following A storage device is monitored. In step 111, the storage system sends an alarm in real time, and compares the performance tables of all storage devices in the standby storage pool, selects a storage device whose performance and space meet the requirements in the standby storage pool, promotes it to the running storage pool, and then removes the storage device on the problematic device The data is reconstructed or migrated on the newly upgraded storage device, so that the data can be read from the new device to ensure the reliability of data access. After step 111 is completed, go to step 110 and load the problematic storage device into the disabled storage pool.

In step 108, the system performs work performance analysis (such as detecting data throughput, average response time, read and write correctness) to the storage device in standby state, if the performance of the storage device is higher than or equal to a specified value, step 112 is performed; If the performance is lower than the specified value, step 114 is performed. In step 112, if the system finds that a new running storage device needs to be added to meet the requirements of data storage, the running state of the storage device in the system will be marked as running, and transferred to the running storage pool to store the newly added data . In step 114, the system transfers the standby storage device whose performance does not meet the requirements into the disabled storage pool.

In step 109, the system further analyzes the physical performance of the storage device, such as detecting the controller load (note: when a disk drive receives a read or write request from the host, the disk controller must spend a certain amount of time for and Transferring data between buses and decoding and interpreting requested commands, this process is called controller load), seek time, data read/write time, zero cylinder damage of storage devices, failure of blocks in storage devices If it is found that the physical performance of the storage device does not meet the requirements of the system, then step 116 is performed, and the system automatically or manually takes out the device by the administrator, and replaces it with a new storage device whose physical performance meets the requirements, and then performs step 118 to transfer the new device to the standby storage pool. If the physical performance of the storage device meets the requirements of the system, the storage device is formatted, transferred to the standby storage pool, and the performance table of the storage device is updated, as shown in step 120 .

The present invention also contemplates various variations of the above-described embodiments. For example, the interface of the storage device 4 in FIG. 1 may also be serial ATA, ST506/412, IDE, EIDE, SSA, 1394, USB and other interfaces.

Although the disclosed embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions and alterations could be made to the embodiments of the present invention without departing from the spirit and scope thereof.

Claims (3)

1. evolutionary storage system, the processor that comprises thesaurus and managed storage storehouse, it is characterized in that: the physical storage device (4) in the described thesaurus (2) is divided into operation, standby and three kinds of states of forbidding, and is divided into operation storage pool (21), standby storage pool (22) and forbidding storage pool (23); Described processor (3) is provided with:

Storage service apparatus (10) is used for data I/O request that responsive computer node (1) sends, and data storage service is provided, and the I/O data are sampled, and sends data I/O and distribution characteristics analytical equipment (9) to;

Data I/O and distribution characteristics analytical equipment (9) are used for the frequency of utilization of I/O data and this data are carried out statistical study in the physical location distribution characteristics of thesaurus, send analysis result to decision analysis device (8);

Decision analysis device (8) is used for comprehensively the frequency of utilization and the distribution characteristics result of the I/O data that send from data I/O and distribution characteristics analytical equipment (9), and from installing the memory device serviceability result that (7) send, in evolutionary rule storehouse (11), select evolutionary rule, obtain the control information of formulating in this rule, control command is sent to storage device management device (7);

The operational order that storage device management device (7) sends over according to decision analysis device (8) distributes again or memory device is carried out Regeneration Treatment the data in the thesaurus; And memory device managed, safeguard the logical device unit marks of memory device and the mapping relations table of location number, the running state information of memory device is carried out the real-time sampling analysis, results of performance analysis is fed back to decision analysis device (8);

This system also comprises user management device (12), be used to receive the system I/O and the distribution characteristics analytical information of data I/O and distribution characteristics analytical equipment (9) output, reach the running state information of each memory device of storage device management device (7) output, and link to each other with decision analysis device (8) and evolutionary rule storehouse (11).

2. evolutionary storage system according to claim 1 is characterized in that: described storage device management device (7) comprising:

Storage device performance is monitored sub-device (72) performance of memory device is monitored in real time, and sends the result to storage device management and control sub-device (71);

Storage device management is controlled sub-device (71) and is used to accept the order that decision analysis device (8) sends, the storage device performance that sends control information is monitored sub-device (72), the sub-device of logical device Single Component Management (73) and memory device and is safeguarded sub-device (74), finish the management function of memory device, the status information of memory device is fed back to user management device (12) and decision analysis device (8) respectively;

The sub-device of logical device Single Component Management (73) receives storage device management and controls the logical device unit dynamic configuration information that sub-device (71) transmits, the logical device unit marks of memory device and the mapping relations table of location number are safeguarded, and information is passed to storage service apparatus (10) by decision analysis device (8);

Memory device safeguards that sub-device (74) receives storage device management and controls the memory device maintenance command that sub-device (71) sends, and memory device is safeguarded.

3. an evolvement method that is used for claim 1 or 2 described evolutionary storage systems the steps include:

(1) system monitors each memory device in real time;

(2) state of judgement memory device:

(2.1) when memory device is in run mode, detect its runnability, if performance is undesirable, ALM, and choose the memory device that performance and space meet the demands from the standby storage pool and be promoted to the operation storage pool, and with the reconstruct on this memory device of the data on the original equipment; Otherwise, continue operation and use;

(2.2) when memory device is in standing-by state, detect its runnability, if performance is lower than designated value, change the forbidding storage pool over to, otherwise, change the operation storage pool as required over to or keep original state;

(2.3) when memory device is in the forbidding attitude, detect its physical property,, replace with new memory device, otherwise memory device is formatd processing if performance does not meet the demands; Change the memory device after new or the format over to the standby storage pool again.

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